Prior to the development of oral-cavity-imaging-and-modeling systems, dental practitioners employed mechanical-impression methods to create three-dimensional models of teeth and underlying tissue in order to facilitate fabrication of various types of prostheses, including crowns and bridges. The mechanical-impression technologies generally involved biting, by a patient, into a viscous, thixotropic material that retains an accurate impression of the patient's teeth and underlying tissue when the material is lifted off from the patient's teeth. The material may serve as a mold for casting a positive three-dimensional model of the patient's teeth and underlying gum tissue or as a mold for casting a prosthetic device. While mechanical-impression technologies have been used by dental practitioners for many decades, mechanical-impression technologies are associated with a variety of deficiencies, including a relatively large probability that the impression may be inadvertently altered or damaged during removal of the hardened, viscous, thixotropic material from the patient's teeth as well as during transportation of the impression to laboratories where positive three-dimensional models are cast and prostheses are fabricated. In addition, the procedure is time-consuming and unpleasant to many patients.
More recently, semi-automated oral-cavity-imaging-and-modeling systems have been developed to electronically create digital, three-dimensional models of teeth and underlying tissues from images of a patient's oral cavity captured by an electro-optical-mechanical endoscope, or wand, that is guided by a technician within a patient's oral cavity in order to collect a sufficient number of two-dimensional images from which a three-dimensional digital model of the patient's teeth and underlying tissues is computationally generated. The oral-cavity-imaging-and-modeling systems have proven to be faster, more accurate and robust, and more cost effective than mechanical-impression technologies. However, the efficiency and cost effectiveness of oral-cavity-imaging-and-modeling systems may significantly vary with respect to the experience and skill of the technicians who use the oral-cavity-imaging-and-modeling systems to generate three-dimensional models of patients' teeth and underlying tissues.